Time AdditionCalculator
Sum up multiple time durations in one place. Give each row its hours, minutes and seconds, and the total sum appears in HH:MM:SS and in decimal hours while you type.
Add Time Durations
List each time duration below — the total keeps up as you type.
How the Time Addition Calculator Works
Adding durations takes four quick steps.
Enter First Duration
Fill in the hours, minutes and seconds for the first value. Blank fields count as zero.
Add More Rows
Press "+ Add Row" for every extra duration; each row has its own hour, minute and second boxes.
Auto-Calculation
There is no button to press — the sum refreshes as you type, with base-60 carryover applied automatically.
Read Total
The answer is shown as HH:MM:SS, decimal hours, total minutes and total seconds, so every format is covered.
What Is a Time Addition Calculator?
How time duration addition works with base-60 arithmetic.
Adding time isn't like adding regular numbers
A Time Addition Calculator totals HH:MM:SS durations using base 60, not base 10. 1:30 + 2:45 is not 3:75, because a time can't have 75 minutes — those 75 minutes become 1 hour 15 minutes, for a correct total of 4 hours 15 minutes.
The carryover process
Seconds are added first; anything over 59 is carried into minutes. Minutes are added next, carried seconds included, and anything over 59 moves into hours. This cascading carryover keeps the result in valid HH:MM:SS form every time.
Why you need this
By hand, every extra duration means another round of carrying, and one slip spoils the total. The calculator adds any number of values instantly and without errors.
When to Use a Time Addition Calculator
Jobs where adding time durations by hand would be tedious.
Music & Playlists
Add track lengths to get a total album or playlist length and see whether a set fits its time slot.
Running & Lap Times
Add up lap times or interval splits from a training app to get the full workout time.
Video Editing
Total the clip durations — intro, segments, transitions, outro — to know the final running time before you render.
Manufacturing
Add the processing times of each production step — cutting, welding, painting, inspection — to get a per-unit total.
Travel Itineraries
Combine flight legs, layovers and transfers into one door-to-door figure for a multi-stop trip.
Study Planning
Add up time per subject to build a study schedule that fits the hours you actually have each day.
Time Addition Calculator FAQ
Answers to frequent questions about the Time Addition Calculator.
As many as you need. Each click on "+ Add Row" adds another entry, and every row is included in the running total — even hundreds of them.
No. Any empty field counts as 0, so you can enter only hours and minutes, only minutes, or any mix. Partial rows are added correctly.
They are carried over automatically. 135 minutes in total becomes 2 hours 15 minutes, and 90 seconds becomes 1 minute 30 seconds.
Yes. Put each flight, drive or layover on its own row and the grand total gives your whole journey time in hours, minutes and seconds.
Decimal hours express the total as one number for payroll, billing or a spreadsheet. Note that 2h 30m is 2.50 decimal hours — not 2.30.
Yes. Click the × on that row and it disappears; the total recalculates straight away. At least one row always stays on screen.
Add the seconds, minutes and hours in separate columns. Then convert upwards: every 60 seconds becomes a minute and every 60 minutes becomes an hour. For example, 1:40 + 0:35 = 1 hour 75 minutes = 2 hours 15 minutes.